The invention relates to an apparatus for the production of printing plates comprising a printing down station with a plate table and an associated illuminating means, which station has associated with it a foil receiving means formed preferably by a foil supply cassette for unprinted foil and preferably a receiving cassette for printed foil, in the case of which the foil to be printed onto an unexposed or blank printing plate is able to be taken from a foil receiving means by means of a moving vacuum frame, is able to be moved onto the blank plate on the plate table and after exposure is able to be discharged, preferably into a receiving cassette.
Such an apparatus is described in the German utility model publication 8,813,594 U, in which a vacuum frame is provided in the printing down station under which the unexposed foil supply cassette is moved for taking and releasing foil which is able to be lowered onto the plate table for printing down, i.e. copying the image of the foil onto the plate. In this known arrangement there is a comparatively long time interval between one printing down operation and the next, since after each printing down operation the one vacuum frame has to run through a complete working cycle, before the next printing down operation is possible. The consequence of this is that the output rate is comparatively low. Although attempts could be made to increase output by increasing the speed of motion, this leads to less reliable operation, to noise and to danger of wear.
The German utility model publication 8,528,934 U describes a further device for the production of printing plates which has a magazine provided with compartments for respective pieces of foil and from which a foil is withdrawn by a first vacuum frame which deposits the foil on a feed table, by which the foil is moved into the copying or printing station where it is transferred to a second frame, which lowers the same on the blank plate. After printing down the foil is transferred from the second frame to a delivery carriage, which puts in the receiving cassette. In this known arrangement the foil accordingly has to be transferred a large number of times from one carriage to another. Such transfer operations do however make the apparatus comparatively slow and the production rate is poor. Furthermore, the transfers of the foil reduce the accuracy of printing and may also lead to a substantial deterioration of the foil.